They found low-intensity exercise helped activate the visual cortex, which plays a role in processing things the eyes see.

'GLOBAL EPIDEMIC OF BLINDNESS'

We face a global epidemic of blindness if we continue to spend hours you spend staring at a screen, experts warned earlier this year.

The high energy light emitted from digital screens is causing irreversible damage to our eyes by deteriorating the retinas.

Damage to the retinas - the light-sensitive layer at the back of the eye - is the biggest cause of central blindness.

And Spanish researchers warned 'it is now clearer than ever that we are facing a global epidemic' of sight loss - particularly for the millions of children who are exposed to digital screens earlier than ever.

Study author Professor Barry Giesbrecht said: 'We show that the increased activation - what we call arousal - changes how information is represented, and it’s much more selective.

'That's important to understand because how that information then gets used could potentially be different.'

This comes after researchers at Emory University, in Atlanta, found exercise protected mice from going blind in a study published in 2014.

They noted how it boosted their retinas from age-related degeneration, but suggested the findings could also ring true for humans.

But contrary to both studies, it is widely known that exercise can have the opposite effect - potentially signalling a condition.

Many runners report symptoms of blurry vision after completing their short jog, often as a result of low blood pressure, dehydration or even a lack of nutrients.

However, if it happens frequently experts recommend adults to seek medical advice to make sure it is not as a result of a condition.